: a specific dynamic sub-step index or sim_handle_all. By default a call to simHandleDynamics
executes the dynamics engine x times, with x times smaller time steps (where x is a parameter that can be adjusted). At each of those sub-steps, contacts are created and destroyed. With the dynamicPass argument you can select which sub-step you wish to retrieve contacts from (zero-based index), or sim_handle_all to retrieve the contacts of all sub-steps. See also simGetInt32Parameter
objectHandle: handle of a specific object you wish to retrieve contacts from, or sim_handle_all to retrieve all contacts in the scene.
index: zero-based index of the contact to retrieve. Optionally, you may add sim_handleflag_extended to the index, if you also wish to retrieve the normal vector (see further down)
objectHandles: handles of the two objects contacting. The handles might also refer to particle objects that are not treated as regular scene objects.
contactInfo: pointer to 6 values (or 9 values if sim_handleflag_extended was added to index), where the 3 first values represent the contact position, the 3 next values represent the force generated by the contact, and the (optional) 3 last values represent the normal vector at the contact. The force vector returned by the Bullet engine will omit the component that results from fricition.